{"id":705624,"url":"https://alion.io/job/callosum-inference-engine-development-member-of-technical-staff","title":"Inference Engine Development - Member of Technical Staff","company":{"id":669125,"name":"Callosum","domain":"callosum.com","url":"https://alion.io/company/callosum","size_band":"11-50","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Ashby","truth_index":{"grade":"A","score":95,"open_postings":3,"ghost_share":0,"stale_share":0,"repost_share":0,"time_to_fill_p50_days":100,"computed_at":"2026-11-05T05:54:30Z"}},"role":"AI/ML","role_family":"AI/ML","seniority":"staff","employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["London, United Kingdom"],"countries":["GB"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":149000,"max_usd":290000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":22},"experience_years_min":null,"visa_sponsorship":true,"relocation_package":false,"has_equity":false,"technologies":[{"name":"C++","optional":false},{"name":"Cerebras","optional":false},{"name":"CUDA","optional":false},{"name":"Python","optional":false},{"name":"SGLang","optional":false},{"name":"vLLM","optional":false}],"status":"live","first_seen_at":"2026-05-20T16:36:20Z","employer_posted_date":"2026-05-20","last_verified_at":"2026-11-06T04:22:04Z","board_verified":true,"closed_at":null,"days_open":169,"trust":{"level":"ok","repost_count":0,"flags":[],"days_open":168},"description":"About Us\nWe’re living through a Cambrian explosion of intelligence: new models and new chips, each specialised for different tasks, are arriving all at once. The result is a new era for AI, one of radical heterogeneity.\nCallosum is the Intelligent Systems Company. We believe the next generation of AI won't be defined by any single model or chip, but by intelligent systems in which hardware and intelligence co-evolve. We are building the infrastructure that unifies heterogeneous compute across the full stack. This opens a new axis of scaling intelligence: a dynamic system that tailors itself to what each workload actually needs, whether that's speed, cost, precision, or whatever unit comes next.\nThe last era scaled on a different bet: one bigger model, more of the same chip, more data. That bet is running into structural limits. Frontier models offer extraordinary capability at unsustainable cost, one that today's monolithic infrastructure was never designed to serve.\nOur founding principle is that intelligence comes from many specialised systems working together, not from any single component. We build the software orchestration layer that co-evolves models, workflows and silicon into one system, delivering inference tailored to every workload, and demonstrating orders-of-magnitude leaps in capability and cost.\nBecause our software spans the full stack, our engineering team works directly with heterogeneous accelerators and frontier silicon, including Cerebras, d-Matrix, Intel, NVIDIA, AMD, Normal Computing, Tenstorrent, GreatSky, and Mixx. We are not stopping at today's chips: each new generation of silicon unlocks algorithms that couldn't run before, and we intend to be first to them, every time. If we get it right, it will belong to everyone building on it - not to any single vendor.\nIn our latest funding round, we raised $100M, led by Atomico with participation from Plural, DCVC and the UK Sovereign AI Fund’s first investment. With this, we are building the infrastructure for the next era of intelligence.\nWe are engineers and scientists based in London, working across the full depth of the stack. We are curious, intellectually honest, and building what doesn't exist yet. If you thrive on uncharted territory and are energised by the scale of the challenge, we'd love to hear from you.\nAbout the Role\nCallosum believes that orders of magnitude improvements in AI systems will come through application-aware orchestration across heterogeneous hardware. We are building that vision: infrastructure that treats the full landscape of compute as a unified, co-evolving system, evolved beyond GPUs.\nInference engines were designed for single-model inference on homogeneous GPU clusters - this role builds them beyond that. Working directly on systems like vLLM and SGLang, you will adapt and extend them for heterogeneous resources, making them hardware-aware, with deeper optimisation around scheduling, memory, and execution. The execution strategies you design - parallelism, disaggregation, caching - will define what heterogeneous inference looks like at production scale. Your work ensures that the capabilities exposed by the lower layers of the stack translate into real, measurable gains, the new standard for how inference runs on diverse hardware.\nWhat You'll Build\nContribute upstream to SGLang and vLLM, and maintain internal forks where our requirements diverge\n\nImprove hardware-awareness within inference engines so that scheduling, memory management, and execution adapt to the capabilities of the underlying accelerator\n\nDesign and implement bespoke parallelism and disaggregation strategies that go beyond default configurations to better exploit heterogeneous hardware\n\nWork closely with an Accelerator Systems Software engineer to ensure engine-level abstractions map cleanly onto diverse hardware capabilities\n\nWhat Sets You Apart\nDeep familiarity with the internals of SGLang, vLLM, or comparable inference serving frameworks - scheduler design, memory management, and execution pipelines\n\nStrong background in high-performance Python and C++/CUDA systems, particularly in the context of ML inference\n\nExperience designing or implementing parallelism strategies for large model serving\n\nUnderstanding of disaggregated serving architectures and the tradeoffs involved in separating modules of a workflow\n\nDemonstrable record of working effectively in fast-moving open source codebases with evolving APIs and design conventions\n\nWhat We Offer\nCompetitive Salary, determined by skills and experience\n\nEquity & Ownership\n\nPrivate healthcare\n\nWe offer Visa sponsorship and relocation benefits to hire the best in the world\n\nWe work in person at our London office. You'll have the tools, space and setup to do your best work, and if you have specific needs, just tell us\n\nWe're committed to building an inclusive workplace where everyone feels welcome, and believe in equal opportunities for all.","description_format":"text","description_chars":4949,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Equity"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":true,"industries":["AI Compute & Inference","AI Chips & Accelerators"],"lifecycle":[{"event":"open","at":"2026-09-11T03:51:38Z"}],"visa":[{"country":"GB","licensed_sponsor":true,"evidence":"Licensed UK visa sponsor (Skilled Worker)","filings_12m":null,"filings_prev_12m":null,"green_card_filings_12m":null,"median_offered_wage_usd":null,"route":"Skilled Worker","cap_exempt":false,"checked_at":"2026-11-05T06:29:30+00:00","sources":["UK Home Office: register of licensed sponsors (workers)"],"filings_for_role_12m":0}],"liveness":{"score":25,"band":"fade","label":"Fading","p_open":1,"p_active":0.687,"p_room":0.36,"age_days":168,"expected_fill_days":100,"reasons":["conf:2","win:tail","crowd:"],"computed_at":"2026-11-05T05:54:30Z"},"pay":null,"html_url":"https://alion.io/job/callosum-inference-engine-development-member-of-technical-staff","json_url":"https://alion.io/job/callosum-inference-engine-development-member-of-technical-staff.json","meta":{"generated_at":"2026-11-06T05:24:01Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler_verified","counted_by":"address","units_charged":1,"used_today":9525,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-11-07T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":669125},"rest":"https://alion.io/mcp/rest/get_company?id=669125"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fcallosum-inference-engine-development-member-of-technical-staff"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Fcallosum-inference-engine-development-member-of-technical-staff"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Fcallosum-inference-engine-development-member-of-technical-staff"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/callosum-inference-engine-development-member-of-technical-staff\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fcallosum-inference-engine-development-member-of-technical-staff"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":705624}},{"tool":"search_jobs","arguments":{"company":"callosum.com","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":705624},"note":"people open to offers who fit this vacancy"}],"note":"The same data through MCP tools: https://alion.io/mcp/open needs no sign-in (compact searches, postings, people); https://alion.io/mcp with an Alion account has everything. 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